Hamas responded by firing rockets and mortars into southern Israel. Hamas now has longer range rockets, several hit near the Israeli port city of Ashdod for the first time, 23 miles from Gaza.

At the weekly Cabinet meeting in Jerusalem, Prime Minister Ehud Olmert urged the public to be patient.

Mr. Olmert said the operation could go on a long time and the home front could endure an extended period of rocket attacks.

The Cabinet also approved the call up of more than 6,500 reserve soldiers, indicating that the air assault on Gaza could be followed by a ground offensive. Infantry and armor units are already deploying on the Gaza border.

"We do not necessarily intend to conquer Gaza, but of course we are reviewing all options," said Cabinet Minister Yitzhak Herzog.

Hamas says it won't raise the white flag, and warns that if Israel enters Gaza it will pay a heavy price.

Hamas spokesman Fawzi Barhoum said all options are on the table, including rocket attacks and suicide bombings.